I own the Korg AX3000G and I love it! The tone is superb imo. The special effects are awesome and the ESS is really great for throwing in arpeggio's and trills that you have a great deal of control over. I have a Fender American Deluxe HSS Strat, an Epi LP Standard, and 2 ESP's (one of them I just put a set of Seymore Duncans in...Distortion/Bridge - 59N/Neck!! Awesome metal sounds through the Korg.) and play them through a Marshall 50w combo or a crate 120w combo and they both sound great. The directions are a bit confusing, but after awhile you get the hang of it....plus even if you mess with it and mes it up, there is a default reset to put it right back to the "out-of-the-box" set-up. Iv'e talked to some people who have the GNX4 and they say they hate it compared to the Korg!